Non-shearing rod for strengthening concrete-work



(No Model.)

T. A. LEE. NON-SHEARING ROD FOR STRENGTHENING CONCRETE WORK. No. 505,664.

Patented Sept. 26, L833,

V w u E M/X Q UNITED STATES PATENT FicE.

THOMAS A. LEE, OF KANSAS CITY, MISSOURI.

NON-SHEARING ROD FOR STRENGTHENING CONCRETE-WORK.

SPECIFICATION forming part of Letters Patent N0. 505,664, dated September 26, 1893.

Application filed Nov mber 19, 1892- Serial No. 45 2,486. (No model.)

To all whom it may concern:

Be it known that I, THOMAS A. LEE, of Kansas City, Missouri, haveinvented certain new and useful Improvements in Noirshearing Rods for Strengthening Concrete, Cement, Tile Work, and Like Constructions, of which the following is a description, reference being taken to the accompanying drawings, which form a part of this specification.

The object of my invention is to produce a rod with a verylarge cement engaging surface whereby, when embedded in concrete, or cement and tile work, in the construction of fire proof floors, roofs, ceilings, walls, area walks, partitions, and similar constructions, it may contribute greater strength than is possible with the cement or concrete or tile alone. In most instances the cement and tile work are strong enough to resist the forces of compression and I find it only necessary to employ my rods in the tension members of the construction. The great difficulty with tension rods has heretofore been due to the slip or shear of the rod within the surrounding cemout or concrete, which permits the cement to break apart at any one point a distance equal to the total elongation of the rod. If shearing can be entirely prevented such accumulated stretch is impossible and the rod must be ruptured at any point where rupture of the surrounding mass occurs. Rods with barbs have been used to prevent shearing with some success. ]It has also been found advantageous to use a rectangular bar extending through the mass of concrete and twisted so as to create a continuous bond. The difliculty arising with this latter form, on account of initial strains due to the twisting, materially reduces the strength of the rod as a tension member and limits the angle of twist which determines the pitch of the continuous bond. 1 have found that with good quality iron or soft steel sufficient twist could be given, but with dense high grade steel of much greater tensile strength rupture occurred, when twisted far below the amount which I have considered advisable. By my present invention I produce a bar or rod of high tensile strength, dense steel, provided with comparatively steeply-inclined spiral or helical channels running continuously from end to end and aifording great cement engaging surface with a minimum of cross section and weight of metal employed. Such a rod or bar is preferably formed by laying two or more stiff lwires, bars or strands, after the manner of forming ropes, and with or withouta separating strip to form projecting flanges. The stiff bars, strands, rods, or Wires, so laid-up do not prod uce in the finished bar or cable .the initial strains which would result withan integral bar of steel; and I am therefore enabled to form my rod with a very steep layor pitch, giving a very firm grip within the cement in which it may be embedded, and to employ hard stiff non-stretching steel of great tensile strength.

. In addition to these general features of my invention, my invention consists of and contemplates certain other details, constructed, arranged, combined, and used, substantially in the manner hereinafter described, claimed, and illustrated in the accompanying drawings, wherein Figure l is an isometric projection showing in section a tile fioor provided with one form of my non-shearing rods. Figs. 2 and 3 are respectively a side view and a cross section of the form of my rod shown in Fig. 1. Figs. 4 and 5 are similar views of my simplest form of rod, and Figs. 6, and 7 are similar views of my rod as constructed where unusually great strength and great lightness are required.

Throughout the drawings like letters of refence indicate like parts.

In Fig. l I have shown a tile floor formed by a single layer of tiles, of a form I find advantageous where combined simplicity and strength are desired. The tiles 0 are formed with very 'heavy upper faces 0 to enable them to sustain the compression which occurs in the upper surface or member of a floor construction. Near the lower faces are recesses c which form between adjacent tiles the rectangular tubes for containing my rods embedded in the cement. To facilitate the laying of the cement and tension rods I place the flanges which form the bottoms of the rectangular tubes upon one side only of each tile in order that they may support the cement and the rods while the adjacent tiles are being placed in position. This is not however a matter intimately concerned with the present invention, and as the tile forms the subject of claims in a separate application filed I will not herein more fully explain its details.

In Figs. 4 and 5 is shown the simplest form of my rod, and I will therefore describe this form first. It consists merely of two small circular comparatively stifi bars or rods which are preferably, not necessarily, laid-up spirally, or twisted, in the manner of ropes, without allowing any twist whatever in either of the individual strands. This may be done by securing the two bars or rods together to a rotary head and applying tension individually to the two strands at their opposite ends while leaving them free to rotate severally about their individual axes. This laying may be done in many other ways, which it is not necessary for me to here set forth. When the proper angle of twist has been obtained the rod is cut into the desired lengths according to the span of the floor or other structure in which it is to be used.

I am aware that British patent of 1854 numbered 2,293, shows a series of arches with the abutments bound together by wire rope. The ends of the rope are spread or hirled out to give grasp or anchorage for the ends of the rope. The flexibility of the individual strands of old wire rope made up as they are of sepa rate smaller strands of wires, and the fact that the rope is secured at its ends distinguishes this invention from mine. In my invention, the stiffness of the inclined or projecting ribbons or strands and the considerable depth of the channels formed between are relied upon to receive and firmly grip the cement in Which the rod may be embedded, throughout the entire length of the rod, without any intention of merely bonding together the two extreme ends of the floor. In short, it is the bonding together of immediately contiguous portions of the cement and surrounding tile-work that gives to my rod its necessary functions, for, the rod, if merely employed as a tie rod between the ends of the floor, would not prevent the cracking of the cement at any one point throughout its length.

In Figs. 2 and 3 the structure of the rod is varied by the addition of a fiat strip D which is placed between the strands when they are being laid-up and which forms when finished, as shown, two stifi spiral ribs or flanges, increasing the cement-engaging cross-section of the completed rod.

In Figs. 6 and7 Ishowa construction somewhat similar to the last but employing four strands and two flange strips bent at an angle around opposite strands to form four spiral ribs or flanges. In this last form, for an equal patent I set forth a further development of the construction of rods, adapted to that and to other uses.

In an application filed by me on the 30th day of April, 1892, and numbered 431,369, I have set forth another species of my generic invention, closely allied to the present application but containing claims which could not be made herein. In this present application I claim and desire to secure by these Letters Patent the following:

1. A non-shearing tension rod for the purposes described consisting of two or more bars or stiff strands laid spirally together to form spiral channels for the adhesion of cement, concrete, or other surrounding material, substantially as set forth.

2. A non-shearing rod or bar for the purposes described consisting of two or more bars or stiff strands having spiral channels or grooves between them for the adhesion of cement, concrete, or other material, substantially as set forth.

3. A stiff non-shearing rod for the purposes described having spiral channels or grooves, substantially as set forth.

4:. A non-shearing rod for the purposes set forth consisting of two or more strands, and a plate or plates held in position by the said strands and forming spiral ribs around the said rod, substantially as set forth.

5. A non-shearing rod for the purposes described, consisting of two or more strands and a plate or plates, twisted together, substantially as set forth.

6. A non-shearing rod for the purposes described consisting of strands twisted together, but without twist in the individual strands, substantially as set forth.

In testimony whereof I have hereunto set my hand this 12th day of November, 1892.

THOMAS A. LEE.

Witn esses:

CHARLES W. WATERMAN, ROBERT A. YOUNG. 

